The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Various types of networking technologies have been developed resulting in an unprecedented expansion of computer networks, television networks, mobile communication networks, telephony networks, and the like, fueled by consumer demand. Beyond third generation (3G) wireless systems (B3G) and 4G mobile communication systems are considered to be heterogeneous networks that include multiple radio access technologies (RATs), which may be implemented by corresponding radio access networks (RANs). Examples of such multi-RAT environments include 2G (e.g., GPRS, EDGE), 3G (e.g., UMTS, W-CDMA), 3G transitional (e.g., HSDPA, HSUPA, LTE) or 4G (e.g., IMT-A, LTE-A) networks, a 3G/2G environment or even a cellular/WLAN environment.
Wide area RANs generally provide user equipment with wide area access to the core networks of public land mobile networks (PLMNs), and to other external networks such as the Internet via a respective core network. Another type of network, referred to as a local access network, generally provides user equipment with access to these and other external networks either going through or without going through (bypassing) the core network. Access to the external network without going through the core network may be referred to as a local breakout. The term heterogeneous network is often used to describe wireless networks using different access technologies. In this regard, a wireless heterogeneous network may, for example, provide a service through a wireless local area network (WLAN) and switch to a cellular network while maintaining the service.